How are you uploading your files?
Here is a shot of my server using Filezilla, on the left you can see permissions. by right clicking for properties you will get some options, make sure you can write to these folders write

How are you uploading your files?
Here is a shot of my server using Filezilla, on the left you can see permissions. by right clicking for properties you will get some options, make sure you can write to these folders

I have no Idea about the free hosting, but I doubt it.
in your ftp program you can see the folders and files on your server. Each will have permissions.

attached is a shot of my server files. I haven't used smart.ftp but i am sure it is the same.
By right clicking and getting properties I get the box shown in the second shot if your folders do not have write permission, then that is the problem if they do then it is somewhere else. Try this first